


An Anatomy Lesson

by stained_glass_heart



Series: Inspired by my Mother [1]
Category: Iron Man (Movies), Marvel Cinematic Universe, Spider-Man: Homecoming (2017)
Genre: Baby Peter Parker, Cuddling & Snuggling, Fluff, Gen, Parent Tony Stark, Peter Parker is Tony Stark's Biological Child, Platonic Cuddling, Science, Sleepy Cuddles, Sleepy Peter Parker, Tony Stark Has A Heart, Tony Stark is Good With Kids
Language: English
Status: Completed
Published: 2019-04-28
Updated: 2019-04-28
Packaged: 2020-02-08 17:51:43
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,090
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18628261
Author URL: https://archiveofourown.org/users/stained_glass_heart/pseuds/stained_glass_heart
Summary: Completely self indulgent fluff to start healing from Endgame. No plot at all. Just soft Irondad caring for a baby spiderson.Includes broad generalizations of anatomy, a stubborn carseat, Peter Parker being the most chill baby ever, and no beta.





	An Anatomy Lesson

Tony made sure the sink-bath was structurally sound, blue plastic joints and lime green clasps holding up the navy blue mesh. The tap water, run through one of the most extensive water filters available for private use, was just warmer than body temperature, the exact way the doctors had instructed him to run it (which he then verified with several online sources. He's Tony Stark, for god's sake, he's going to check and verify everything he can before he'd ever let anything happen to...)

A tiny, frustrated squeak comes from the floor, just outside the kitchen. Tony glances over, half panicked, before realizing that Peter, his baby Peter, was just waking up from his nap taken on the car ride home. 

'God,' Tony thought, 'he's so fucking tiny in that carseat.'

And Peter was very much making his frustration with the carseat known. He was screwing his face up in dissent, trying to wave his arms and kick his feet while making grumpy, half asleep noises. All Tony could do was smile fondly, and glance into the living one (last) time, before walking over to Peter, cooing the whole way.

"Why... lookie what we have here. A grouchy baby who doesn't want to sit in the carseat and nap, huh. Well, we'll just have to get you out of that thing then, won't we? Let's see if your old man remembers how to do this, shall we?" Peter blinked up at him with newborn-blues as he pushed his thumbs into the red buttons on the side of each handle, pushing it back with a series of clicks. "There we go, there's that done. Now the visor..." again pushed back, "and now to the hard part. You'd think these would be a little easier to operate for an engineer, wouldn't you, kid? But oh no, this monstrosity of brightly coloured plastic tells me nothing."

Tony sighed, again, and started with the red button that sat right at Pete's hip-line. The stupid button was so stuck, he had to try pressing it three times, before figuring out he could press with one hand, and pull the connecting straps with the other, until they all released. Peter was still blinking at him with confusion, and he had to admit he must have made a sight. Disheveled hair, bitten off curse words, knelt on the floor, and wild-eyed, just trying to undo a carseat. Tony took a "cleansing breath", as his therapist of the week was calling it, and looked back down at the baby watching quietly, and without blinking, which would have been creepy if it weren't in every parenting manual Tony had devoured that babies didn't blink as often as adults.

"Worst part's over, baby," he said, "this is the last thing to get you out of here and into your bath, scrub all that hospital off of you." Then he went right back to work, loosening the shoulder straps, unclasping them, then lifting Peter with one hand bracing the back of his neck, and one spanning all the way from his diaper, up his back. 

Peter gurgled at the disturbance, but settled quickly, burying his face into Tony's collarbone, and clasping onto his shirt as soon as it touched his open palm. It took Tony's breath away, and he just stood there for a minute, in awe of the bursting love and adoration in his heart for this tiny, amazing, wonderful person he was now responsible for, and would be for at least the next eighteen years, and even after. 

Quickly recovering, and blinking away the burning tears trying to surface, Tony turned his face down to his son, "Alright chicky, let's get you clean now." And he turned and walked slowly to the sink, careful not to jostle the poor, sleepy boy too much. He laid the baby on the dry mesh in the sink, and unsnapped the blue and grey airplane-print onesie and carefully slid it off of each arm, then lightly tugged it off of each tiny ankle. Then, he unwrapped the diaper, lifting it away carefully, and starting the water back up. The bathing went smoothly. The soap he had chosen was lavender scented and not too strong, and was made for babies with skin as sensitive as Pete's. Washing his hair was funny, playing with the soft pieces, and twisting and standing them up lightly, while the baby made a face like he couldn't figure out what was happening, even though he could feel every bit of it. 

Finally, Peter was clean to Tony's satisfaction, and was starting to wriggle, ready to be all done. "Easy squirt," Tony chided gently, "Don't squirm your way out of here."

He pulled the towel closer to him, from where it had been resting on the countertop. The robot design had been Rhodey's choice, and Tony smiled every time he saw it. Keeping on hand gently on his baby's stomach, he stretched the towel out, and wrapped Peter in it softly, lifting him into his arms, and using a loose corner to gently dry his soft, fine hair. 

Then, they started walking toward the living room, where Tony had made the decision to camp out for the night. Walking in, he called out gently, "Hey J, drop the lights for me, would you? Just the lamps on for now."

"Of course, sir. Anything for you and the Young Sir." As J.A.R.V.I.S spoke, the overhead lights dimmed out, and the few lamps around the room cast out a warm, gold light. J.A.R.V.I.S had also taken the liberty of tinting out the tower's west-facing windows, blocking out the later-afternoon sunshine and heat. 

"Here that, Petie-pie? You're already J.A.R.V.I.S's favourite, and you've been here maybe all of 45 minutes." Tony watched fondly as Peter scrunched up his eyes and yawned hugely, showing off his bright pink and curling tongue, before smacking his lips together. "Ah, yeah, I bet you're getting hungry, huh, kiddo? It has been about 3 hours, right? Guess we should get you cozy and fed, then. And nap. That too, I could use one right about now."

He walked the four steps down into the living-room inset, which he chose specifically because it was padded enough to sleep on, and the floor didn't have deep seams Peter could get stuck in, like a normal couch. He had already laid out everything they'd need for their camp-out: the diaper bag packed with four changes of already-washed clothes for Peter, a canister of preemie formula that was supposed to be non-colic, bottles, a rollable changing pad, the organic cotton diapers with the green label that Pepper said was the best for sensitive skin, wipes, a large burp-cloth, a baby swaddler, and a light quilt for Tony. 

Holding Peter across his chest with his left hand, Tony braces himself with his right to sit criss-cross on the padded floor, and unrolled the changing pad. Then he gently deposited his precious bundle on it's back, smiling at his son's sleepy eyes. Humming quietly, Tony carefully unwrapped the towel from Peter, and set it to his side. The next step was the diaper, impossibly tiny on his tiny baby. Pulling out the red and navy footy pajamas with the mitten clasps to keep Pete from accidentally scratching himself, Tony turned back to see Peter still watching him, gurgling to himself. 

"Hmm? Whatcha thinking about, Peter pumpkin eater? You seem to be having a wonderful monologue there." Tony unclasped the suit, and leaned forward over his son. "Alright, kiddie, here's what we're going to do. I'm going to lift you forward, get the better part of this behind you, then we'll put each extremity through one at a time. We'll be just fine. Right? Can't be that bad."

Tony was furiously counting his blessings that Peter was being so easy-going about the whole thing. He had read horror stories on parenting forums about preemie babies that wouldn't stop screaming, couldn't be calmed, or kept their parents awake 24/7. Not that he would have as big of an issue with that last one, he didn't sleep much at all in any case. 

Biting the metaphorical bullet, Tony slowly lifted Peter's head forward, via a gentle hand under the back of his head and neck. His other hand went to laying the pajamas behind his son, and he began giving soft words of reassurance when Peter began fussing lightly.

"Hey now, we're alright, kidlet. Just got to be so careful with your head, there's so much amazing stuff back here," Peter sniffed lightly and looked at him with big, tearful eyes, "Yep, absolutely incredible what you've got in this noggin of yours. See back here," Tony rubbed lightly at the back of Peter's head and neck, "is your brain stem, cerebellum, and occipital lobe. Respectfully, those are in charge of your involuntary bodily actions, balance, and eyesight. Now up here," and Tony stroked his fingers over the back half of the top of Peter's skull, "is your parietal lobe. That's in charge of your language learning and tactile sense. That's why when you lean a language, you want to be physically working with something that you associate with the language. Repetition doesn't hurt either."

By now, Peter had calmed, listening to his father's voice, but Tony was on a roll. "These here," he said, stroking behind his son's ears, "are your temporal lobes. Technically, there's only one, but it stretches across your whole brain, so for our purposes now, we'll call it two. And this," he said, with a kiss to Peter's forehead, "is your frontal lobe. It is very important, because all your logic and reasoning and emotional regulation will come from there. Remember, having emotions is good, and having healthy ways to cope with them is great.

"There are other things in there too, like your amygdala and spinal cord, but we don't need to get into those right now. And the whole thing is surrounded by bone to protect it. That's called your skull. Your skull hasn't fully developed yet, it's still made of mostly soft plates that'll fuse together as you get older. That's what allows for your brain to grow as you do!" 

Then Tony picked up each of the pajama arms, Peter having been laid back flat, and very gently. Starting with the right arm, Tony stuck his thumb onto Peter's palm so he grasped, and lifted it lightly. "Good kid, that's an evolutionary quirk, meant to help you grip onto thing with your fingers, especially a tree branch or a parent. Now what you're grabbing with are your phalanges, they all have three joints and a whole lot of power relative to your body size. The special ones are your thumbs," Tony said, dropping a quick kiss to it, "they're opposable, which means you can grasp things from a number of directions, and they give you better control. Not that you've learned how to use that yet."

Tony got the bunched-up arms over Peter's wrists, stopping to rub his thumbs gently over Peter's tiny arms. "Under here are two bones, your radius and your ulna. You can remember which goes on which side by remembering the P in 'pinkie' comes before the T in 'thumb', and that the R in 'radius' comes before the U in 'ulna'. Boom. There you go. Those connect to your elbow.. Yikes! Kid, warn a guy before you decide to fling your hand into his face. Yes, I see you have very good control of that elbow. And shoulder. We were having a moment, let's get back to it, please. Oh yes, from your elbow, there's your humorous, which connects to your shoulder and clavicle."

Tony paused to gently rest his hands along his son's shoulders and take a deep breath. Since this was keeping Pete calm and focused, and might be the only way he survives this first night home, he figured he might as well keep going. "Alright, your shoulders and clavicle are important because they give you two things: mobility, and a framework structure for your ribs and spine. But we'll come back to that in a minute. I think I'd like to not have your feet getting cold." So he gently pulled the feet attachments down, and slid the tiny feet into them. 

"You know, your toes have phalanges too, and meta-carpals, and carpals, just like your hands. They can even curl, kind of like your hands do, just a little less." Tony ran his hands over Peter's legs, the doctors told him the physical contact would be helpful in giving his son's nervous system proper input. "Your carpals are in the joints that connect your hands and feet to your arms and legs. For your hands, that's all in the wrist. For your feet, that's in the ankles. Now connected to your ankles are your tibia and fibula. I don't have a fancy trick for remembering those. The fibula is on the outside, and the tibia is on the inside," he explained, snapping the snap-clasps closed on both legs, up to Peter's knees. "You don't have well developed kneecaps yet," he said, "those will come in later when you're better suited for crawling and walking. Give it some time."

Snapping the snap-clasps higher, he said, "these are your femurs. They're the most durable bones in your entire body. When you're an adult, they'll be about as hard as concrete, and a full quarter of your height. They connect to your hip-bone, your pelvis, which helps your spine stay in place, and has the joints to move your legs. And this," he said, blowing a raspberry Pete's belly while he lightly kicked out, "is your gut, belly, or stomach. It has a whole bunch of muscle groups called organs, whose first and foremost job is to take the things you eat, get the nutrients out of them, and send the waste out." As he talked, he snapped more snap-clasps closed. 

"And this here," he said, brushing across Pete's chest, "is your rib cage. It had true ribs, that connect to your breastbone, and false ribs, that connect to one another. They protect two very important organs. Well, two of one kind, and another. The first thing they protect are your lungs: you've got one on the left," and Tony tapped Peter's left side, "and one on the right," as he tapped Peter's right side. "The one on the left is just a little smaller to make room for the other organ that's very important: your heart. Now your heart has three very important jobs. One, it oxygenates the blood in your body as it moves through. Two, it twists and squeezes to send that oxygenated blood all through your body. And three, it has a simple brain of it's own that communicates with the big brain upstairs. It responds best to emotions, and is tied up with the brain stem.

"So that's all your body basics, straight from your Dad," Tony said, as he finished up the clasps to the onesie. "Why don't we grab you some food and head to sleep. I think the hospital really took it out of both of us." 

Peter, he just yawned again, now that he was no longer watching his father so closely, the exhaustion was really setting in. Tony smiled, fond and gentle, and scooped Peter up and into his lap, nestled in the crook of his left arm. Peter's bottle had been premade, and stuck into a portable bottle heater while he got cleaned and dressed. So, Tony just grabbed the burp cloth from the bag at his side, lay it over Peter's clean pajamas, and picked up the bottle from the warmer with his right hand. He shook the bottle, just to disturb any of the settling, and popped the clear plastic cap off the top. 

Peter latched onto the bottle as soon as it was presented to him. Tony held it at an angle that was just enough of a flow without rushing the baby, so to keep it all from coming back up later. Peter nursed with soft noises and grunts any time the bottle moved under Tony's hands, and Tony raised his eyebrows every time the sounds got a little too accusatory. Just looking at his son, Tony was in absolute awe. Soft, almost blond hair, just growing in in soft wisps that haloed around his head. Newborn-blue eyes that would probably settle into a rich brown as he got older. Tiny, tiny hands, already holding onto the bottle and trying to push it higher, even though Tony was mush stronger. His son was so incredible. The light of his life. The world on it's axis. His raison d'être. And by God, did Tony ever want to make this world better for his son to see. 

But for now, what Tony could do, was to pull the empty bottle away from his baby, mop up his spills with the corner of the burp cloth, and put the cloth and his son up to his shoulder, sleepy as they both were. He gently patted Peter's back, and rocked back and forth, patting hand cupped and soft. He hummed a mindless tune and waited for the two small burps Peter gave to be all done. Then, he softly brought Peter back down to settle in his arms, deciding to forego the swaddler. He took each mitten flap on the pajamas, and snapped them closed over Peter's wrists. Then, he laid his son flat on his back, moved away all the packed supplies, and lay down next to him, spreading the quilt out over his legs and stomach. He tucked Peter into his chest, an arm caged over the top of his son, and let out a huge yawn, which bright-eyed Peter copied. 

Tony snorted, "Lights out, J. And put this place on Do Not Disturb. No one else gets in without my say so, not even Rhodey or Pep. And wake me in four hours if Peter doesn't by then."

"As you wish, Sir," was J.A.R.V.I.S's reply, even and ready as ever. And with that, Tony looked down at his son, who had already settled into closing his eyes, head turned toward the warmth of his father's chest, and smiled. He closed his eyes, and said, "Night J. See you soon." 

And the two of them drifted off to sleep.

**Author's Note:**

> I hope you all enjoyed if you made it to the end here!! If you want more of this, tell me, because this is my first work in the irondad fandom. So.... love you all!!!


End file.
